Art, Common Core, etc.
Microsoft Educator Network
History & Geography PBL Lessons - Hub Pages
Science PBL Lessons - Hub Pages
Five Keys to Rigorous PBL
Twenty Questions to Guide Inquiry Based Instruction
PBL Tools from Start to Finish
Check list for rigorous lessson plan - You know your is rigorous when...
Check lists, tutorials, step-by-step guides for creating units that include rigor
Rigor and Relevance Example Lesson Plan
Three Simple Strategies for More Rigorous Instruction
Increasing rigor throughout the lesson - data driven classroom best practices
Lesson Plan Samples